WHEN?

Major facilities such as airports are not typically named for politicians while they are still in office.

President Obama's second term of office ends in 2016. If previous precedent is followed, then it is unlikely that an airport will be named for him while he is still in office.

Of course, Barack Obama has set quite a few new precedents, so naming an a new Obama Airport before then is certainly a possibility. Most likely, an airport naming (if any) will occur shortly after he leaves office in 2016.